For two weeks starting Friday, Microsoft will pre-sell Windows 7 upgrades for as little as $50.

"As a way of saying thanks to our loyal Windows customers, we are excited to introduce a special limited time offer," Microsoft spokesman Brandon LeBlanc said in an entry to a company blog early Thursday.

Microsoft offered a similar deal prior to the launch of Windows Vista three years ago.

"For customers in the U.S., Canada and Japan, starting tomorrow on June 26, they will be able to pre-order a copy of Windows 7 for delivery on October 22 of either Home Premium or Windows 7 Professional," said Brad Brooks, vice president for Windows consumer marketing, in a video interview posted alongside LeBlanc's blog post. "[For] Home Premium in the U.S., pricing will be $49.99, and the Professional version will be $99.99."

Those figures represent a reduction of between 50% and 58% from the standard list prices for the upgrade editions of Windows 7 Home Premium and Professional. Orders can be placed with participating retailers, such as Best Buy and Amazon.com, or at Microsoft's own online store.

The pre-order discount prices are valid from June 26 through July 11 in the U.S. and Canada, but end July 5 in Japan. Customers in the U.K., France and Germany will be offered similar pre-order discounts starting July 15, said LeBlanc.

Microsoft's pre-order discount was not a surprise. Several weeks ago, a leaked memo from retailer Best Buy had disclosed the limited-time pricing plan.

Microsoft also revealed list prices for Windows 7 today, cutting the price of only one of the three retail editions, even though consumers face tough economic times.

"We are reducing the [list] price of our most popular retail product for customers, the Home Premium Upgrade, by approximately 10%, depending on the market," said LeBlanc. Those prices will be in effect Oct. 22, when retailers start selling the new operating system, and computer makers begin selling Windows 7-equipped PCs. More reading: